Help Plastic Greenhouses - I cooked my sweet peas :(

[hobbity]

Hi, I'm a beginner at the veggies lark and I've just proudly bought a little upright greenhouse with a plastic zip up cover. I put some sweet pea seedlings in there which had been on my window sill and it got so hot in the first morning that I steamed them and they look terribly sad.
I've also got a thin fleecy cover for it which I'm now using to give it a bit of shade so that it doesn't get too hot during the day or cold at night. How else should I control the temperature? Leave the zips open? How sensitive are seeds to temperature before they germinate??

Thanks

Oops. I did the same to my sweet peas last year - luckily they regenerated themselves!!

I always unzip my plastic greenhouse in the mornings and only zip it up at night if it's forcast to be very cold. Sweet peas are pretty hardy and I've planted mine out now.

The other propblem I've found with this sort of greenhouse is how easily it disintegrates in the wind, I've taken to jamming a heavy wooden chair up agaist it to stabilise it.

Mine took off yesterday scattering seed compost everywhere haven't had the heart to sort it all out yet.